Session Initiation Protocol (SIP) is an open signaling protocol for establishing many kinds of real-time communication sessions. Examples of the types of communication sessions that may be established using SIP include voice, video, and/or instant messaging. These communication sessions may be carried out on any type of communication device such as a personal computer, laptop computer, Personal Digital One key feature of SIP is its ability to use an end-user's Address of Record (AOR) as a single unifying public address for all communications. Thus, in a world of SIP-enhanced communications, a user's AOR becomes their single address that links the user to all of the communication devices associated with the user. Using this AOR, a caller can reach any one of the user's communication devices, also referred to as User Agents (UAs) without having to know each of the unique device addresses or phone numbers.
Call tracing in traditional communication systems is relatively easy because a most messages transmitted during a communication are relevant to that communication (e.g., are content bearing messages). When SIP is used, however, many messages from a particular endpoint or IP address are not useful for that call. For example, SIP utilizes many messages that are not content bearing messages and are, therefore, not necessarily needed for call tracing purposes. Thus, there is no current solution for call tracing intelligently in a SIP environment.
Traditional call tracing solutions apply a single filter for identifying calls of interest that are subject to a call tracing mechanism. The filter criterion usually includes an originator identifier and a target identifier. For example, a call tracing filter criteria may indicate call tracing should occur for any calls from IP address ‘A’ to IP address ‘B’ or vice versa. The problem with using these traditional mechanisms in a SIP environment is that these simple filtering criteria can trigger call tracing for relatively unimportant or unwanted SIP messages, thereby unnecessarily occupying call tracing resources and call recording resources.